ISX400 Intermittent and varying boost pressure
10-19-2022, (Subject: ISX400 Intermittent and varying boost pressure ) 
Post: #1
ISX400 Intermittent and varying boost pressure
I got to think others have had this problem and will be reading posts about low or inconsistent boost. In the meantime I will tell some details of what the problem is to which I seek what I should be looking at. For about 10 years I have driven a 2010 T2000 ISX400ST. The whole time it has been inconsistent boost pressure from one mountain to the next and even from gear to gear on the same hill. I have seen it anywhere from 15 to 35+ psi on any given day. Recently while in the rolling hills approaching the northbound scale at Anderson CA. I felt the power drop off to almost nothing, I saw the boost drop before my eyes from 30 down past 20, 15, 10, 5,.... No smoke in the mirrors, no check engine light, a couple of downshifts and it WAVERED it's way back up around 25psi. I stopped to have it checked in Redding before starting up the Siskiyou's where they told me the turbo was worn out. 2 weeks, a rental truck, plus $7500 later I hooked back onto the trailer and started north with a reman turbo but still my old actuator. On the very first hill climb up to Shasta Lake I didn't think I was going to make it. Below 20psi and down shifting as fast as I could I crawled over the top. The next hill a little better at 25 or so. Most of the 6%ers it was 20 to 28 showing on the gauge all the way through Oregon and Washington up as far as JBLM where it miraculously pumped up to 35+ at full throttle and ran the last 15 miles or so like I think it should have been for the whole 10 years I have driven this truck. I think the turbo never was / is not now the real problem. Cummins did a $22,500 inframe a few years back, but that had no effect on this issue. What other things are involved with determining how much boost the turbo makes? Sensors? Circuits? Advice? Thank you.
replyreply


Messages In This Thread
ISX400 Intermittent and varying boost pressure - Vman - 10-19-2022



NOTE: Rawze.com is not affiliated, nor endorses any of the google ads that are displayed on this website.